Automated interference mitigation in frequency division duplex (FDD) wireless networks

Abstract

A method is disclosed for use in a frequency division duplex (FDD) wireless network including a base station (BS) and a user equipment controller (UE) communicating through a medium having an uplink communication channel supporting communications from the UE to the BS, and a downlink communication channel supporting communications from the BS to the UE. The method includes identifying an uplink frequency spectrum in the uplink communication channel affected by an interfering signal, and determining the uplink power level of the interfering signal and whether the interfering signal is caused by passive intermodulation distortion (PIM). In response to determining that that the interfering signal is caused by PIM, the method includes adjusting, based on the uplink frequency spectrum and the uplink power level of the interfering signal, one or more of a downlink power level of a downlink transmission signal and a downlink frequency range in the downlink communication channel.

What is claimed is: 
     
       1. A method for use in a frequency division duplex (FDD) wireless network, the method comprising:
 identifying a frequency spectrum in the communication channel being affected by an interfering signal; 
 determining whether the interfering signal is external to the FDD wireless network; 
 in response to determining that the interfering signal is external to the FDD wireless network, determining whether a frequency spectrum of the interfering signal changes as a function of time; 
 in response to determining that the frequency spectrum of the interfering signal changes as a function of time, identifying a rate of change with respect to time of the frequency spectrum of the interfering signal; and 
 selectively scheduling transmissions over the communication channel to avoid the interfering signal based on the rate of change with respect to time of the frequency spectrum of the interfering signal. 
 
     
     
       2. The method of  claim 1 , wherein the interfering signal is caused by a passive intermodulation distortion (PIM). 
     
     
       3. The method of  claim 1 , wherein the FDD wireless network comprises a fourth generation wireless systems (4G) technology network utilizing a Long-Term Evolution (LTE) standard, and wherein the method further comprises:
 in response to determining that the interfering signal is external to the FDD wireless network, scheduling no downlink signal transmission during some LTE downlink subframes. 
 
     
     
       4. The method of  claim 1 , wherein the FDD wireless network comprises a fifth generation wireless systems (5G) technology network, and wherein the method further comprises:
 in response to determining that the interfering signal is external to the FDD wireless network, scheduling no transmissions over another communication channel during some slots. 
 
     
     
       5. The method of  claim 1 , further comprising:
 reducing a number of transmission resource blocks used for transmissions over another communication channel. 
 
     
     
       6. The method of  claim 1 , further comprising:
 decreasing a power level of some transmission resource blocks used for transmissions over another communication channel relative to others of the transmission resource blocks. 
 
     
     
       7. The method of  claim 1 , further comprising:
 turning off at least one of a plurality of downlink transmission resource blocks used for transmissions over another communication channel. 
 
     
     
       8. The method of  claim 1 , wherein identifying the frequency spectrum in the communication channel being affected by the interfering signal is based on in-phase (I) and quadrature phase (Q) components within a receiver. 
     
     
       9. The method of  claim 1 , further comprising:
 using a configuration index (CI) of a physical random access channel (PRACH) of the FDD wireless network to avoid interference between the interfering signal and the PRACH. 
 
     
     
       10. The method of  claim 1 , wherein selectively scheduling includes at least one of (i) scheduling the transmissions at an edge frequency of a frequency range in the communication channel, or (ii) scheduling the transmissions from a remote device during one of a low-PIM 4G LTE subframe and a low-PIM 5G slot. 
     
     
       11. A device for use in a frequency division duplex (FDD) wireless network, the device comprising:
 a hardware processor configured to:
 identify a frequency spectrum in the communication channel being affected by an interfering signal; 
 determine whether the interfering signal is external to the FDD wireless network; 
 in response to determining that the interfering signal is external to the FDD wireless network, determine whether a frequency spectrum of the interfering signal changes as a function of time; 
 in response to determining that the frequency spectrum of the interfering signal changes as a function of time, identify a rate of change with respect to time of the frequency spectrum of the interfering signal; and 
 selectively schedule transmissions over the communication channel to avoid the interfering signal based on the rate of change with respect to time of the frequency spectrum of the interfering signal. 
 
 
     
     
       12. The device of  claim 11 , wherein the interfering signal is caused by a passive intermodulation distortion (PIM). 
     
     
       13. The device of  claim 11 , wherein the FDD wireless network comprises a fourth generation wireless systems (4G) technology network utilizing a Long-Term Evolution (LTE) standard, and wherein the processor is further configured to:
 in response to determining that the interfering signal is external to the FDD wireless network, schedule no downlink signal transmission during some LTE downlink subframes. 
 
     
     
       14. The device of  claim 11 , wherein the FDD wireless network comprises a fifth generation wireless systems (5G) technology network, and wherein the processor is further configured to:
 in response to determining that the interfering signal is external to the FDD wireless network, schedule no transmissions over another communication channel during some slots. 
 
     
     
       15. The device of  claim 11 , wherein the hardware processor is further configured to:
 reduce a number of transmission resource blocks used for transmissions over another communication channel. 
 
     
     
       16. The device of  claim 11 , wherein the hardware processor is further configured to:
 decrease a power level of some transmission resource blocks used for transmissions over another communication channel relative to others of the downlink transmission resource blocks. 
 
     
     
       17. The device of  claim 11 , wherein the hardware processor is further configured to:
 turn off at least one of a plurality of downlink transmission resource blocks used for transmissions over another communication channel. 
 
     
     
       18. The device of  claim 11 , wherein identifying the frequency spectrum in the communication channel being affected by the interfering signal is based on in-phase (I) and quadrature phase (Q) components within a receiver. 
     
     
       19. The device of  claim 11 , wherein the processor is further configured to:
 use a configuration index (CI) of a physical random access channel (PRACH) of the FDD wireless network to avoid interference between the interfering signal and the PRACH. 
 
     
     
       20. The device of  claim 11 , wherein selectively scheduling includes at least one of (i) scheduling the transmissions at an edge frequency of a frequency range in the communication channel, or (ii) scheduling the transmissions from a remote device during one of a low-PIM 4G LTE subframe and a low-PIM 5G slot.